1. Field of the Invention
This invention relates to a novel trisphenol hydrate. More particularly, it relates to 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane hydrate which melts at much lower temperatures than the melting point of 1,1,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane.
2. Description of the Prior Art
1,1,3-Tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane is in wide use as an antioxidant for such high-molecular substances as natural and synthetic rubbers, polyethylene, polypropylene, other polyolefins, polystyrene, polyesters, poly(vinyl chloride) and ABS (acrylonitrile-butadiene-styrene) resins. According to U.S. Pat. No. 3,196,185, for instance, this compound is produced by condensation of crotonaldehyde and 3-methyl-6-tert-butylphenol and recrystallized from toluene, whereby a crystalline product having a melting point of 180.degree.-182.degree. C. is obtained. As desired, this product is recrystallized from petroleum ether (boiling point: 80.degree.-100.degree. C.) and dried under high vacuum at 100.degree. C. for several hours, whereby a product melting (with decomposition) at 188.degree. C. is obtained.
However, when such a purification method is employed, the crystalline product prepared by recrystallization from toluene, for instance, naturally and characteristically contains a considerable amount of toluene. Use of such a product as it is as an antioxidant is undesirable from the viewpoints of odor and health hazard. Although heating at 120.degree. C. for 3 hours, for instance, can eliminate the toluene, such heating may undesirably cause discoloration of the product.